The present invention concerns relatively high molecular weight epoxy resins cured with conventional curing agents wherein the relatively high molecular weight epoxy resin is prepared in situ in the presence of the curing agents.
Lee and Neville in HANDBOOK OF EPOXY RESINS, McGraw-Hill, 1967 have disclosed products obtained by curing advanced epoxy resins.
While these cured products have good properties, application of the mixtures of epoxy resins and the curing agent are very difficult in that they are highly viscous, are difficult to devolatilize and at a temperature sufficiently high to achieve a suitable viscosity, the working time or pot life is relatively short.
The present invention provides a method for easier application in the form of lower application viscosities, thus allowing lower application temperatures and extended working time or pot life and an improvement in one or more of the properties of the cured product such as glass transition temperature (Tg), fracture toughness (G.sub.IC), impact, flexural modulus, percent elongation, and the like.